Jack



July 21, 1925.

G. L. BUTTA JACK Filed Jan. 215, 1925 e f X 08 AL A h o o W 7 n; o X 5 f Giovanni Luigi Butiw,

lmren/tor.

Patented July 21, 1925.

UNITED STATES GIOVANNI LUIG-I BUTTA, OF CONCORD, NEW SOUTH VVALES, AUSTRALIA.

JACK.

Application filed. January To all whom it may concern:

Be it known that GIOVANNI LUioI BUTTA, subject of Great Britain, residing at El Retiro, Correy Avenue, Concord, in the State of New South ales, Commonwealth of Australia, has invented certain new and useful Improvements in Jacks of which the following is a specification.

This invention relates to lifting and lowering jacks of the kind comprising a threaded load-lifting or lowering member engaged by a toothed wheel meshing with two toothed wheels which are alternately rotated in opposite directions by reversely arranged pawls carried by an oscillatory manipulating structure. I v

The object of the invention is to provide an improved jack of this kind, which is of simplified construction and which can be adjusted into operative position and reversed for lowering with a minimum of trouble and waste of energy.

With these general objects in view the invention consists in the structure hereinafter described and more particularly pointed out in the appended claim.

Referring now to the accompanying drawings which illustrate one convenient embodiment of the invention,

Figure 1 is a side elevation partly in section,

Figure 2, on the right side, is a front elevation and on the left side is a section on the vertical aXis of Figure 1,

Figure 3 is a sectional plan on the line 3-3 of Figure 1 and Figure 4: is a sectional plan on the line 4.-4 of Figure 2.

The improved jack stands upon aloase plate a, integral with which is a vertical hollow standard or casing 6. Towards the top of the casing are provided a pair of aligned horizontal trunnions 0 upon which are mounted toothed wheels d and e. A bevel gear f is adapted to mesh with the bevelled portion of the teeth on wheels cl and e and is axially bored and screw threaded to receive a threaded load-lifting and lowering member g. The wheels d and e are formed with bosses 72, and 6 respectively which fit rotatably on the trunnions c.

Pawls j and 7c engage the fiat portions of the teeth of wheels cl and 6 respectively. These pawls are slidably housed in cylindri cal casings Z and m which screw into bores in structure comprising parallel side arms 15, 1925. Serial No. 2,666.

a which terminate in bearings 0 rotatably mounted on the bosses h and i. The casings Z and m have large bores for guiding the pawls and reduced bores for receiving the stems of the pawls. In the larger bores helical compression springs p are arranged. The pawl casings have notches or recesses g, with which pins 1" on the pawl stem engage. The pawl stems have suitable milled heads 8 and lock nuts t may be provided to secure the pawl casings in position. i

The arms a carrying the pawl casings are extended inwardly as at u the extensions being bent into the plane of the lifting member 9 and secured together by screws 4), one part being extended still further to furnish a handle w.

The top of the load-lifting member 9 is provided with any suitable bearing block 00 and adjacent the bottom of member 9 is provided a pin 3 which projects into channels a formed in the casing b. The pin 3 being in engagement with the stationary casing b, prevents the member 9 from rotating with out preventing it from rising or falling. The channels 2 are closed at the top to limit the upward movement of the lifting member, and open at the bottom to allow for placing the lifting member in position or for removing such member for any purpose.

In operation the pawls are set in opposite directions as indicated in Figure 3 and by means of the handle w, the pawl carrying structure is rocked up and down. As shown in Figure 3, the upward stroke rotates wheel d which results in the rotation oi wheel f in a clock-wise direction and a con-- sequent rising of the load-lifting member 9. During this upward stroke the pawl 75 slips idly over the teeth of wheel 6. During the downward stroke of the handle to the pawl 70 rotates the wheel 0 and thus continues the rotation of wheel f and ascent of the member g. If a load is to be lowered, it is merely necessary to grasp the heads 8 and withdraw the pawls against the action of springs 79 far enough to bring the pins 1* out of the recesses The pawls are then turned through a half turn and upon being released the pins 1" again fall into the recesses q. The working faces of the pawls thus being reversed, the rocking of the handle will now cause counter-clock-wise rotation of wheel 7 and lowering of member 9.

The invention thus provides a simple construction which eliminates lost motion and.

provides a double acting arrangement which can be reversed very quickly and easily. A further considerable advantage which the invention gives lies in the fact that to bring the bearing block m initially into engagement with the load, it is not necessary'to raise the member 9 by rocking the handle w. For this purpose the member 9 can be raised or lowered very rapidly by lifting it to the Wheel out of engagement with wheels d and .0. The wheel 7 is then spun i eundby hand to, bring it to the desired distance from the bearing block, depending on height of the load, and the member g is then lowered to bring the wheel f into mesh With the wheelts (Z and 6.. Load lift ing can thus be proceeded with immediately without wasting time in raising the load in a step by step movement.

It will be understood that the form of the invention described and illustrated is given by way of example, and that any constructional; variations may be-madeiwithin the V op of he appe ded c a m-f I claim:

A comprising a vertical tubular standard, axially aligned, 1 horizontal trunnions adjacent the top, of the standard, a toothed wheel mounted on each trunnion, a

screw threaded load moving member freely slidable vertically in the standard at all times when the jack is unloaded, PIOJBC- tions adjacent the bottom of said member slidable in a vertical. channel in the standard, a nut on said member having teeth resting by gravity alone in mesh with the toothed wheels on .the standard, a bifur cated frame pivoted on said trunnions, and a pair of devices comprising independently reversible pawls carried by said frame and engageable with said toothed wheels, the pawl devices each comprising a casing screwed into bores in the bifurcated frame, said casings having a large bore for the pawl and a'small'bo're for thepaWl stem, a

pin on the pawl stem engageable ith a recess in the outer end of the casing, a head on the outer end of the stem, a lucknut on the casing and a compression spring 1n the larger bore behind the pawl, they end of the pawl having a flat ope ative'face substantially in line with. the axis of the stem and a bevelled face adapted to slide, over the teeth of the toothed wheels. c

In testimony whereof I aflix my signature in presence of two Witnesses. V GIOVANNI LUIGI BUTTA.

lVitnesses: I

H. M. Mortars, L. V. MAGUIRE. 

